"Lord God, I come to you a sinner, and I humbly repent for my sins. I believe that Jesus is Lord. I believe that you raised Him from the dead. I will ask that Jesus will come into my life and be my Lord and Savior. I receive Jesus to take control of my life that I may live for Him from this day forth. Thank you, Lord Jesus, for saving me with your precious blood. In Jesus' name, Amen." —Intro to Good Kid, m.A.A.d City by Kendrick Lamar

The first time the rapper Lecrae spoke to Kendrick Lamar, more than five years ago, he called him after hearing the song "Faith" from Lamar's self-titled 2009 EP — the first project the Compton, California, rapper, previously known as K. Dot, released under his birth name. "Faith" has a classic, modular narrative structure — like Eminem's "Guilty Conscience," or TLC's "Waterfalls" — with three interlocking verses about people whose belief in God falters under life's cruel gravity. The first verse is rapped in the first person, and resolves with Lamar devastated by the real-life murder of a friend. "Life is too much, I'm just through," BJ The Chicago Kid sighs on the hook. It's heavy stuff.

"It touched me and I reached out to him like, 'Hey, can I talk to you about it?'" Lecrae recalls. Lecrae, who topped the Billboard 200 last fall with his seventh album, Anomaly, and won a Grammy for Best Gospel Album in 2013 (he's nominated for the first time in a non-gospel category this year, Best Rap Performance), is widely acknowledged as the most successful artist ever to emerge from the Christian hip-hop community. "We started talking and that's really how our relationship began."

The two artists — typically thought of as occupying two distinct, non-overlapping worlds in the hip-hop universe: secular and Christian — stayed friends after the "Faith" call, communing, and occasionally commiserating, about life as imperfect believers who happen to rap.

"In this industry, a lot of people shake hands and high-five each other, but there's not a lot of genuine conversation about the deeper things in life," Lecrae says. "When you're struggling with your girl or your mom is sick, it's rare that you find someone that actually wants to talk with you on a real level. So being able to connect with him on spiritual matters is definitely something that I value and appreciate."

Save for the reliably blasphemous Kanye West, no rapper established in the upper echelons of popular music is more vocal about his personal religious beliefs than Lamar. Though he has never neatly fit the description of what would usually be termed "Christian hip-hop," Lamar has often seasoned somber soliloquies of navigating the gang culture that birthed him with Christian themes of good and evil, as well as the redemptive power of Jesus Christ. Since the release of his platinum-selling, Grammy-nominated major-label debut Good Kid, m.A.A.d City in 2012, and a reported baptism while supporting West's Yeezus tour in 2013, the centrality of Christianity to Lamar's worldview has only grown more obvious.

In a recent Billboard interview, Lamar credited favoritism from God for his deliverance from the gravitational pull of crime in his neighborhood, and then casually declared his belief that the apocalypse is near. "We're in the last days, man — I truly in my heart believe that," he said. "It's written."

Speaking to Complex last year, he revealed his conviction that his career is divinely inspired. "I got a greater purpose," Lamar said. "God put something in my heart to get across and that's what I'm going to focus on, using my voice as an instrument and doing what needs to be done."

In a later interview with Houston's 93.7 The Beat, Lamar extended that sense of purpose to all of humankind: "We're all put on this earth to walk in His image, the Master," he argued.

And in The Fader in November, Lamar explained his decision to dress as Jesus Christ for Halloween this way: "If I want to idolize somebody, I'm not going to do a scary monster, I'm not gonna do another artist or a human being — I'm gonna idolize the Master, who I feel is the Master, and try to walk in His light. It's hard, it's something I probably could never do, but I'm gonna try. Not just with the outfit but with everyday life. The outfit is just the imagery, but what's inside me will display longer."

Lamar's fitful efforts to live out his faith have always rippled along the surface of his music. He has a fondness for using songs as parables, in which the horror of violence and rote debasement of humanity can only be tempered by the grace that comes from a higher power. On an instructive unreleased song called "Jesus Saves," Lamar spins a narrative enumerating the everyday pestilence of the inner city — guns, homelessness, fatherlessness, unemployment, incarceration — and thanks God for saving him from the fate of his peers despite being an unrepentant sinner. His voice cracks as he repeats the eight-word chorus over and over: "I don't know why He keeps blessing me."

Unlike most Christian artists who come from a traditional gospel background, like Kirk Franklin or Steven Curtis Chapman, Lamar has never restricted his purview to a discussion of things that are holy. For an incredibly famous rapper, his personal life may border on the ascetic: He doesn't go to strip clubs like Drake, or smoke like Lil Wayne; he rarely drinks and has been in a monogamous relationship since before he became famous. But rather than preach about living a moral lifestyle, he gives full voice to his internal struggles and those of the people he grew up around, deliberately speaking in the language of transgressors.

In the Bible, there is some precedent for this approach. Jesus famously broke from thousands of years of religious dogma by breaking bread with those thought to be morally and spiritually compromised, extending the gifts of God to prostitutes and the unclean. In Mark 2:17, he makes the case for the church to be more accommodating. "It is not the healthy who need a doctor, but the sick," he says. "I have not come to call the righteous, but sinners."

Yet the level at which Christians are to engage with non-Christians is disputed. In a later passage, John 15:19, Jesus says that his followers are not "of the world" but chosen out of it, a distinction that makes them hated.

Lamar's upbringing was not particularly religious. He has said his parents didn't raise him in the church, and credits his grandmother with providing him early exposure to biblical teachings. Although he reportedly thanked his bishop at the 2013 show where he announced his baptism, Lamar has never been publicly affiliated with a particular church or denomination.

His ease at moving in the secular world, affinity for profanity, and evolving attitude toward faith are what originally defined Lamar as a mainstream hip-hop star, and not a Christian one. And within the Christian community, his overtures toward Jesus have so far been regarded with some skepticism.

"A lot of it is trust," says Lecrae. "It's a question of whether or not you're heralding sacred things in your music, and what your motive is. To mainline Christians, there are certain cultural nuances that are acceptable and not acceptable. And I think for them, Kendrick doesn't fall in line with that."

Chad Horton, co-owner of the influential Christian hip-hop blog Rapzilla, agrees, citing explicit Lamar songs like "Bitch, Don't Kill My Vibe" as anathema to core Christian music fans, even though he says he is personally a fan.

"Some Christians might hear Kendrick rapping about God or Jesus and still reject it, because even though he says he's Christian, they listen to his other songs and look at his lifestyle and might not feel like they reflect what a Christian is," Horton says.

Frank Micelotta / AP

Lamar's touring set in 2013, including a prop wall emblazoned with the message "Jesus Is Lord."

But if Lamar's secular indulgences have alienated him from a Christian audience, his Christian impulses may be a handicap with the secular crowd. The central irony of Lamar's career is that he is a noble soul at the vanguard of a culture that rewards the ignoble — a good kid who not only survived the mad city, but got elected mayor.

The occasions where Lamar has been the most successful have been when he's allowed his moral compass to stray from true north, as on the transparently anomalous singles "Backseat Freestyle" and "m.A.A.d. City," or disguised a righteous message to the point where it can be safely ignored, as on "Swimming Pools (Drank)." "i," the first single, released in September, from Lamar's forthcoming follow-up to Good Kid, failed to fit this formula, wearing its message of self-love and spiritual resilience on its sleeve.

"I done been through a whole lot / Trials and tribulations but I know God," the lyrics begin over a soulful Isley Brothers sample. "Satan wanna put me in a bow tie / Praying that the holy water don't go dry."

"i" has so far been a misfire both critically and commercially — leaving many reviewers scratching their heads, barely cracking the top 40 of the Billboard Hot 100, and fizzling at radio. Ebro Darden, former programming director for Hot 97 and host of the station's Ebro in the Morning show, acknowledges that "i" underperformed. But he doesn't think that morally uplifting content, by Lamar or others, is necessarily at a disadvantage in hip-hop.

"We've seen hits come from that category," Darden says. "Kirk Franklin had mainstream success. We've had rappers that were Five Percenters, like Rakim and Busta Rhymes, who rapped about Five Percent knowledge. So I think it all comes down to quality of content, entertainment value, and a fanbase that's interested in what you have to say."

But Lecrae, who began walking the tightrope between Christian and mainstream audiences with his popular Church Clothes mixtape in 2012, says there's a stigma that can come with being viewed as morally superior.

"A lot of times, when people listen to hip-hop, they want to be motivated toward something," Lecrae says. "And if I want to be motivated toward turning up, having a good time, and partying, and you're saying something that's going to convict me, that doesn't motivate me to do what I wanna do. It's an instant turnoff."

The remarkable balancing act Lamar achieved on Good Kid, m.A.A.d City — with tales of both salvation and transgression rendered in vivid, irresistible detail — established a template that has made him both culturally and commercially successful. The real trouble with "i" is its suggestion that enlightenment may push him more toward one end of the good/mad spectrum than the other — that on the other side of spiritual turmoil might actually be inner peace.

As was the case with Malcolm X, the human rights iconoclast to which he has often compared himself, a righteous awakening may not make Lamar more popular in any of the spheres that would seek to contain him. Instead, it could serve to complicate and deepen his output in fascinating and unexpected ways.